Athletic footwear generally tends to be uncomfortable when used for strenuous athletics over a long period of time. This uncomfortable feeling is often caused by the body heat and the consequent perspiration of the wearer's foot, that is built up and retained in the footwear. The normal confining nature of most athletic footwear accentuates these conditions. For example, in basketball and tennis footwear, the upper is normally made of leather or canvas integral with a rubber or synthetic plastic sole. Although leather and canvas uppers do have some porosity which will allow "breathing," such "breathing" is generally insufficient to provide the desirable comfort when the footwear is used for normal athletic purposes.
Attempts have been made to enhance the breathability of footwear by modifying the upper. In some cases, the upper is made with several eyelets in the instep to allow air into and out of the footwear. In other cases open weave uppers have been used. Insofar as known, few or no modifications have been made to the shoe sole to enhance ventilation of athletic footwear.
Eyelets in the instep region of the shoe upper do not provide completely satisfactory results. It is believed that eyelets in the instep region do not allow air to circulate under the sole of the foot where perspiration is significant. Nor do the eyelets in the instep region of athletic footwear provide a positive force for circulating air into the footwear. In addition, such eyelets are often inconsistent with the aesthetic design of the footwear since they are normally visible when the footwear is worn.
Open mesh uppers also limit the range of possible foot-wear designs and therefore have limited commercial value. In addition, mesh or netting type uppers do not afford as much protection and may wear more poorly than leather or solid canvas uppers.
For these and other reasons there is a need for athletic footwear with improved means of circulating drying and cooling air in the footwear. In addition, there is also a need for athletic footwear with improved sole gripping qualities.